The present invention relates to apparatus for rapid inspection of flat-rolled products while on-line at relatively high temperature with an accuracy, ease, and economy heretofore unknown in the industry utilizing ultrasonic detection of internal defects in flat-rolled products through streams of liquid applied to the flat-rolled products and synchronization of the flat products on the mill line with the automatic electronic instrumentation of the apparatus.
Available apparatus of the type of the present invention have one or more of the following disadvantages such as a much higher initial cost or maintenance cost, less inspection coverage, causing an obstruction of the passline, not being capable of reliable inspection at temperatures above 150.degree. C. and not being able to follow contour variations. Designs with one or more of these disadvantages are found in closely related patents U.S. Pat. No. 3,625,051; Belgium Pat. No. 744,628; and U.S. Pat. No. 3,979,946 referring to ultrasonic measuring and inspecting systems.
Also the synchronizing of product motion for operation of the automatic controls as attempted in prior art devices now in use are designed with these devices mounted above the mill line and therefore present an obstruction along the line which prevents a crane from placing or removing anything in the area of the device.